Odds of cancer from TSA scanners about the same as terrorist blowing up your plane

Arizona State University physics professor Peter Rez calculated the amount of radiation exposure a human is likely to receive in one of those newfangled Rapiscan porno-scanners the TSA is so fond of, and determined that exposure to be roughly one-fiftieth to one-hundredth the amount of a standard chest X-ray.

He calculated the risk of getting cancer from a single scan at about 1 in 30 million, "which puts it somewhat less than being killed by being struck by lightning in any one year," he told me.

While the risk of getting a fatal cancer from the screening is minuscule, it's about equal to the probability that an airplane will get blown up by a terrorist, he added. "So my view is there is not a case to be made for deploying them to prevent such a low probability event."

And in that same MSNBC item,

A group of scientists at the University of California at San Francisco laid out their concerns in a letter to the U.S. Food and Drug Administration, highlighting in particular the potential for the X-ray dose concentrated on the skin to pose a health concern for children and other vulnerable populations, such as people with HIV.

"We are unanimous in believing that the potential health consequences need to be rigorously studied before these scanners are adopted. Modifications that reduce radiation exposure need to be explored as soon as possible," the letter said. Among the signers were David Agard, John Sedat (a professor emeritus) and Robert Stroud, all professors of biochemistry and biophysics; and Marc Shuman, professor of medicine.

64 Responses to “Odds of cancer from TSA scanners about the same as terrorist blowing up your plane”

granted, i am not the person who should be pointing out statistical fallacies. but, anyone else see the flaw in comparing rates of cancer from x-ray exposure (a relatively fixed relationship; expose me to x-rays of a certain type every day, and my risk of developing cancer is X amount) to the rate of something extremely fluid and variable, like the rates of a terrorist blowing up a plane? So many factors enter into whether someone wants to commit a terrorist act: recent political events, a sudden increase in certain philosophies being spread within a community, the death of an important figure in a community, etc, causing terrorist attack rates to rise or fall dramatically. A comparison of terrorist attacks and cancer rates, thus, shouldn’t be a number we use to determine whether these machines are necessary.

Pay attention to what this guy is saying. A 1 in 30 million chance? 700 million people a year fly in this country, so 23 people a year get cancer. Remember that you can’t compare the danger on a per-flight basis (in the case of a terrorist) and a per-person basis. Not to mention that some people are more prone to radiation-induced cancer than others.

BB, you’re smarter than this headline. The probability of 1 in 30E6 is conditional upon strong security measures. True, there’s room for improvement in these security measures, but your presentation of this statistic is misleading.

Sure it’s conditional. But if that’s what it was before implementation of scanners, then even if scanners reduce it, they can’t reduce the total probability of getting killed because they have added on a comparable value.

Thank goodness I live in a “third world” country where we can’t afford this kind of high tech crap at airports. We also don’t have to take our shoes off and are allowed to fly with as much liquid as we want!

Seriously, I don’t think I’m ever going to fly into the U.S. again until this is sorted out. I’m not willing to be sexually assaulted and/or irradiated for the “privilege” of visiting your country.

In my opinion, it is about control and conditioning. Those in Government and the elite class with the clout or private transportation as in private planes do not have to do this. Since the foundation of 911, the building block for a police state has been implemented. Our Country has been hijacked our Constitution has been ignored with the unconstitutional patriot act. Most incidents in the news of terrorist threats were hand picked and conditioned by government agencies to justify to the public the need for this security.

“While the risk of getting a fatal cancer from the screening is minuscule, it’s about equal to the probability that an airplane will get blown up by a terrorist, he added. “So my view is there is not a case to be made for deploying them to prevent such a low probability event.”

The idea that the security measures in place has helped lower the probability of an attack may be true, but it’s a bit difficult to prove. The number of attacks prevented and worse, deterred, can be whatever the authorities want it to be. The attacks could not be happening because they’re too hard to carry out, or simply because there’s nobody wanting to do it. Neither can be proven, and at best we can only count the number of people caught in the attempt. Which reportedly, these scanners still might not do.

No, because this statistical analysis is from a “single scan” and this is made explicitly clear.

Radiation dosages can have a cumulative effect that is different than just rolling the dice 3 times instead of 1 time.

Also I remember from my diagnostic imaging classes a lot of calculations involving the irradiation of the entire premises during X-Ray imaging but I forgot the specifics. The fact is that X-Rays bounce off of objects and also scatter in addition to traveling in a straight line . . . these things are pretty much operating all day long and in the middle of an open area, not in a room with thick walls with lead shielding.

The best prevention to terrorist attacks is to not illegally invade and occupy other nations, then steal their natural resources and pollute their land.

“Boogie boogie boogie!” Are you scared? Probably.

Bombarding citizens with radiation is no sure safeguard to anything. Are you willing to undergo rectal cavity searches to calm your paranoid delusions? It’s safer to you than X-rays and to your fellow passengers than exterior scanning.

Dude, chill out- I never said these new security measures are justified, in fact I’ve been saying the opposite (read the rest of the thread). The comment you replied to was a simple statement of the fact that both risks (death by cancer and death by terrorism) are higher for people who fly frequently than people who don’t.

I don’t know why you would expect anything from the FDA, they lost pretty much the entirety of their power of the past decade and can only resort to shaking a fist angrily while scolding the people they feel are making an unsafe product. It’s in a major state of decline because of that, and understandably so.

All this complaining about new screening and not one suggestion on a better way to do it.

Why do we need a better way to do it? Existing, less invasive screening tactics seem to be working pretty well. The two guys who managed to smuggle explosives on American passenger jets since 9/11 only succeeded in getting beat up by fellow passengers and/or burning their own balls off.

Indeed, I concur. Why do we need a better way? No other country on earth is doing this idiotic and invasive procedures, and not one plane has been downed by explosion, anywhere, since what…Lockerbie in 1988?

Do you have any idea how many flights there are per day? I don’t, either. But I know it’s more than ~100,000. ~100,000 flights per day, ~365,000,000 flights per year….for years….and one explosion back in the 1980’s? So…billions of flights….only one commercial airliner bombing in 22 years….

Have you maybe considered how easily you are bending over and taking it, just for some incredibly minuscule, infinitesimally unlikely threat?

Considering just domestically, airlines carried over 600 million people last year (per governmental Bureau of Transportation Statistics), I suppose if the 1 in 30 million people figure about getting cancer is to be believed, that would equate to over 20 people getting cancer a year from these machines.

And what if someone has a predisposition of getting cancer in their family? They have not done enough of testing and the cancers can show up years later. The risk could be higher than they think for those people, seniors, and children.

@HarvardPhD: the scanners have proved ineffective, they are not catching more items through the security gates (Google up the studies from this week).

It does not matter that the proportion is .000003% to use these scanner, over a year, it still translates into 20 free cancers to the US population in the name of Security (800 million passengers per year).

As for your personal choice of going to Burning Man, more power to you. But that is /your/ personal choice, not *our* personal choice.

Just wait until the first death attributable to a poorly maintained machine.

This country really does a shitty job of prototyping and maintenance.

I can already hear the lawyers sharpening their quills and scratching out the law suits.

The beauty of “privatizing” security to Chretoff’s little outfit is that the survivors of ANYTHING having gone wrong get to ram “Little Mikey’s” ass into a meat grinder, (unlike they would if the TSA employees were really using a government developed X-Ray machine.)

Of course they may need to buy extra hats for their kids as a “side-effect” of the radiation.

Personally, I’m more worried about cancer than a TSA agent rubbing one out to my blurry black and white representation. Honestly, I hope someone is actually doing that, then at least someone would be getting something out of my radiation dose.

Of course the major factor in the probability of carcinogenicity is dosage. So for the TSA goon that stands by the scanner every day all day the odds of cancer (over that of a terrorist attack) becomes nigh certain.

And no, the shielding on these things aren’t very good at all. Several images on the web have shown ghost images on the scan of people standing quite far off.

As an x-ray tech, I can say the goon’s risk is not a concern considering the distance (best form of shielding) and energies that the goon’s use. They may (MAY) be issued dosimeters that monitor their exposure to radiation. I bet it’s a tiny fraction of what I get every month.

Well, sure, if you fly occasionally, it’s likely no worse than standard medical diagnostic tests. Concern over radiation exposure for passengers is a distraction from the real civil rights issues.

But X ray techs wear lead aprons for a reason, and in the same vein, to expect pilots and flight crews to go through the scanners every day (which the TSA seems to be doing) is stupidly exposing them to needless risk.

But if you are a woman over 40 you still have a much better chance of being killed by a terrorist than getting a job. And if the screeners hadn’t been keeping us so safe, the odds of getting killed would still be much better.

That’s because your odds of getting a job are 0.0 (as Dean Wormer would say).

At the risk of sounding arrogant, I have a PhD from Harvard in radiation biology. While I also share the privacy concerns and weariness of profit fueling this screening tool, I am equally dismayed by the radiation scare tactics used to strike fear. The public doesn’t listen to risk ratios if the word “radiation” proceeds it.

Unless the public really understands proportional risk, then there will always be profit made at their expense. Worse yet, the egoist physicians who know nothing about the 70 years of rad bio research and claim ” we dont know the effects of radiation”. Irresponsible reporting…. That tactic has been used by Blue Cross sponsored MDs to try to kill heart disease detecting CTscans: “they cause cancer, let’s ban them”… Without mentioning that 1:3 people die of HD and the risk of radiation induced cancer is 1:5000 for the average 60 yr old! Hmmm…. Why would a health insurer want to kill a test that detects heart disease 20 yrs before it standard techniques??? Profit baby.

I went through an airport scanner with my pregnant wife… So, I stand by my risk ratios.

Finally, why is everyone so hung up (no pun) on being seen blurry naked? One thing I can attest to: at burning man , I find that it usually takes me 2 hours to get used to seeing so many naked body parts. After that, they really are background noise and indistibguishable. Put simply, naked people are really not that interesting in aggregate.

The questions raised by the ucsf letter are exactly the point I’m making. Without citing the decades of research about what we do know about rad bio, the letter is just meant to inflame media questions and distract from the real questions that need to be asked. The CT analogy I made was actually referencing another UCSF doctor who critiques any achievement in ct imaging by saying “we dont know About the risks”, despite the fact that mountains of science actually clarify the risk quite well. In science media terms, it’s a political tactic to fan flames.

Again, I’m not saying the scanners are effective, nor needed, but the responsible journalist or scientist needs to put the risks in proportion (ie compared to the burger the passenger just ate, or jaywalking across the airport drop off)), and throw up the radiation smoke screen.

Perhaps you’d like to present your credentials. An anonymous commenter making vague, yet sweeping claims about a team of scientists at a world-class research institution isn’t likely to convince anyone.

I stated in my first post: PhD in Radiation Biology from Harvard (joint program between Harvard Med and MIT). i’ve been involved in Radiation Bio > 20 years, including the past 5 as a writer and researcher focused on the effects of radiation induced cancer due to medical tests, including risk ratios, medias portrayal and political battles using those ratios. I’ve presented to NASA and WHO.

The cited expert in this field is Dr Mahesh at Johns Hopkins. Look up the NPR interviews/etc conducted when scanners first came on the scene. Somehow, the short term memory of the media has forgotten about the real science he cited…. A group of retired dermatologists, X-Ray crystollagraphers, and other tangentially related field non-experts from UCSF would not be able to assess the risks as compared to the int’l independent expert panel they call for that has been convened for 20+ years now: the BIER report.

Finally, did anyone check the ASU physicists math? People hear “professor” and they run with it. Prove to me the calculations, including the estimated deterrence factor of reduced attempts due to the scanners in place, and then we can look at this objectively.

Finally: the irony of all this is that I’m opposed to the escalation of any privacy intrusion. I believe the preventive measures begin with foreign policy and end with rational probabilistic detection… But My point is: if you are going to do this assessment, do it right!

“Without mentioning that 1:3 people die of HD and the risk of radiation induced cancer is 1:5000 for the average 60 yr old!”

Read the fucking article. The risk of getting cancer from these machines is subtantially less than that of getting struck by lightning, but it’s still higher than that of getting killed by terrorists even before these machines were introduced. So even if these machines ELIMINATE the chance of getting killed by terrorists FOREVER, then they kill more people than they save, and they kill by cancer(i.e. year upon year of torture) rather than near-instant incineration. They also make it harder to bring in sensible measures like sniffer dogs and Israeli-style behavioural recognition training because “we done got that magic machine and it cost so much! It’s gotta be perfect!”.

Your excerpt of my post is not congruent with your profanity laden retort. I didn’t argue that the scans were effective, I just pointed out that their are many factors to determine the cost vs benefit ratio of the scans. As soon as people see radiation as a factor, all other variables are disproportionately weighted or ignored.

Finally, your argument about risk of lightening vs radiation only holds true if you presume (a) the machine manufacturers don’t find a way to lower the dose (which has occurred with CT machines) and (b) the terrorist attacks are going to stay at the same rate… Which seems unlikely to me considering what seeds we sewn over the past 9 years.

I hate these things and I hate the fascist direction the USA is taking.

However, if the assumptions in this letter are exactly true, then the logical result is the scanners pass the cost-benefit analysis. If the risk from the radiation is exactly the same as the risk of dying from a terrorist blowing up your plane then the added economic harm and general panic resulting from an airplane blowing up would tip the balance in favor of the scanners.

I do not, however, believe or trust the corporation manufacturing these things to do adequate safety studies or to report the findings truthfully if they were adverse to their product.
If it turned out the danger from radiation was higher than the danger of a terrorist blowing up your plane then the scanners would not be worth having.

Of course all of this is based on the belief that the important factor the authorities are considering is our personal safety, which is not true.
We have to add into it political gain, profit for the manufacturers, and many other factors that unfortunately will weight heavier in congress’s and the TSA’s decisions than our personal safety.

Chance of dying from cancer as result of scanner: 1 in 30 million. Chance of that plane you got scanned to get on blowing up in terrorist attack: 1 in 30 million. The TSA just doubled the chance that your flight will kill you. I bet if you told people that before you polled them, you’d get much lower numbers of people saying “it’s worth it”.

What’s the chance the plane will randomly fall out of the sky and crash anyway? I bet it’s greater than 1 in 30 million. Are we breathalyzing every pilot before they board a plane? Are we rigorously testing the mechanical ground crew for technical aptitude before we give them a wrench?

Part of this outrage isn’t the chance of cancer, it’s the fact that airline travel has resulted in a police state in airports to pretend we’re helping prevent one of the most unlikely dangers of air travel.

Ground crew doesn’t even get scanned or checked. All these years, and ground crew has been doing what they always do, namely, just swiping a “security” card to access those planes. Isn’t it amazing that one of those “cave dwelling” terrorists, who could learn how to fly planes better than seasoned pilots, haven’t been able to figure out how to plant a bomb on a plane by accessing through the ground crew? Boy have we been lucky, huh?

Putting aside the Bill of Rights aspect for a moment, these scanners are really ineffective, and therefore are quite dangerous. Yes, they allow an observer to see metal objects (even a Glock has metal parts and cartridges) but these are easily detected with simple metal detectors. What the scanners can’t detect are explosives, not even the underwear bomber explosives that spawned the TSA demand for these machines.

Explosives (even PETN) are best discovered with ‘sniffer’ technology, which is very reliable and almost laughably inexpensive. In combination with metal detectors, you have almost foolproof security (there will never be 100% foolproof security) at far less expense and without the overly intrusive methods we’re facing today. I should point out that if we don’t halt the TSA’s progressive assumption that we’ve given up our rights, we’ll be facing wireless ‘taser cuffs’ next, the next actual TSA proposal in the pipeline. Imagine an inflight malfunction of that system, in addition to the rather deeper implications that symbolically and in reality, we’ve become prisoners in our own country.

Porno-scans and invasive “pat-downs” really suck. What also really sucks is that “they” (whoever they are), are free to deploy these scanners to hundreds of airports without being able to give conclusive statements about their safety. The fact that people are obliged to subject themselves to these scans without any positive assurance of their harmlessness is ludicrous.

No. That math simply doesn’t hold. In one of the earlier press releases, the TSA has assured us that these new scanners have already found 130 forbidden items and prevented them from going on the aircraft. Do you notice the hidden statement in there? Those same items would have slipped past the old metal detectors. Is it that much of a push of the imagination to think that they probably already did?

Or how about this. By pure accident, I had a full-sized leatherman in my backpack on a flight a few years back. I flew to my destination and it wasn’t until the return flight that the TSA found the device. My punishment was to loose a fine Leatherman, but they let me board. By your logic, since I had the knife and I had gotten it past security, I would have used it. But I didn’t. Why do you suppose that is? A knife by and of itself is not dangerous. It is the intent of the person carrying the knife that matters. To paraphrase the NRA, weapons don’t hijack airplanes, people do.

How do you define a “deadly weapon”? I know people who have trained extensively in martial arts for years. They are a deadly weapon. So they don’t fly? What about your car keys? Used properly, you can seriously mess people up. How about a ball point pen? Used properly, I can kill a person with it.

My final part of this rant is this. When we were told, so many years ago, that the tree of liberty must be watered with the blood of patriots, why do we assume that means somebody else? If you want a free country, a free society, etc. that means you have to accept the risks that come with it. I accept that risk every time I fly. I have faith in myself and my fellow passengers that any terrorist on that flight is not going to succeed in another 9/11-style attack, even if it kills us to do it. Literally.

That’s just silly reasoning. And it makes no sense. “100% that someone”? So on any given plane at any given time there is a 100% probability that if someone on that plane could bring a weapon onboard to hurt people/take over they would? That doesn’t follow. It’s making huge assumptions, not the least of which is that about one in every couple hundred people is out to hijack a plan and/or kill someone on said plane. If that were the case, I actually think people WOULD be hijacking/killing people on planes more often. Because the point of a lot of the protest to this sort of thing? is that it makes no sense, and doesn’t work. I have no doubt that people can and probably do bring deadly weapons on to planes all the time–probably usually by mistake. But also because, well, a pen/book/laptop/suitcase/shoelace/pretty much anything can be a weapon.

And yet…I hardly ever see anyone kill anyone else on a plane, and it’s been quite a while since I’ve been on a hijacked plane. Well, you caught me, that’s never happened to me. Because people on planes? Usually they just want to get somewhere.